Effect of tea polysaccharides on faecal microbiota and their short-chain fatty acid metabolic products

Abstract

To explore the effect of tea polysaccharides on the gut microbiota and their short-chain fatty acid (SCFA) metabolic products, we used the faecal microbiota to simulate the gut microbiota in vitro, and cultured them to obtain a preculture solution. Ultrapure water, tea polysaccharides, and glucose were added to the precultured solution for anaerobic fermentation. Samples of each group were harvested at 0, 6, 12, and 24th hour during fermentation to test the contents of the SCFAs. In addition, high-throughput 16S rRNA sequencing was performed to analyse the microbiota in the fermentation medium. Results showed that the faecal microbiota used tea polysaccharides to generate SCFAs. When compared with the fermentation group with the addition of ultrapure water, the group with the addition of tea polysaccharides increased the relative abundance of Firmicutes, and decreased the relative abundance of Bacteroidetes at the phylum level. The relative abundances of Butyricimonas, Roseburia, Eubacterium rectale group, Ruminococcus 1, Lachnospira, and Parasutterella increased significantly at the genus level. Based on the LEfSe analysis of key microbiota at the genus level, significant differences between the groups were observed. It was clear that tea polysaccharides selectively enriched the microbiota to produce SCFAs, and the correlation between the SCFAs and faecal microbiota was confirmed.